© ISO 2014 Flexible cellular polymeric materials — Determination of fatigue by constant load pounding Matériaux polymères alvéolaires souples — Détermination de la fatigue par indentation à charge con[.]
INTERNATIONAL STANDARD ISO 3385 Fourth edition 2014-07-15 Flexible cellular polymeric materials — Determination of fatigue by constant-load pounding Matériaux polymères alvéolaires souples — Détermination de la fatigue par indentation charge constante ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Reference number ISO 3385:2014(E) Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST © ISO 2014 ISO 3385:2014(E) ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - COPYRIGHT PROTECTED DOCUMENT © ISO 2014 All rights reserved Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission Permission can be requested from either ISO at the address below or ISO’s member body in the country of the requester ISO copyright office Case postale 56 • CH-1211 Geneva 20 Tel + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland ii Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2014 – All rights reserved Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ISO 3385:2014(E) Contents Page Foreword iv Scope Normative references ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - Principle Apparatus Test pieces 5.1 Shape and dimensions 5.2 Samples showing orientation 5.3 Number 5.4 Conditioning Procedure Expression of results 7.1 Loss in thickness 7.2 Loss in hardness 7.3 Percentage hardness loss Precision Test report Annex A (informative) Typical loading cycle Annex B (informative) Precision 10 Annex C (informative) Precision study — Machine Type B 12 Bibliography 13 © ISO 2014 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST iii ISO 3385:2014(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work of preparing International Standards is normally carried out through ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part In particular the different approval criteria needed for the different types of ISO documents should be noted This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part (see www.iso.org/directives) Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights ISO shall not be held responsible for identifying any or all such patent rights Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsible for this document is ISO/TC 45, Rubber and rubber products, Subcommittee SC 4, Products other than hoses This fourth edition cancels and replaces the third edition (ISO 3385:1989), which has been technically revised ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - iv Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2014 – All rights reserved Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST INTERNATIONAL STANDARD ISO 3385:2014(E) Flexible cellular polymeric materials — Determination of fatigue by constant-load pounding Scope ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - This International Standard specifies a method for the determination of loss in thickness and loss in hardness of flexible cellular materials intended for use in load-bearing applications such as upholstery It provides a means of assessing the service performance of flexible cellular materials based on rubber latex or polyurethane used in load-bearing upholstery The method is applicable both to standard size test pieces cut from slabstock material and to shaped components The measured loss in thickness and loss in hardness are related to, but are not necessarily the same as, the losses likely to occur in service This international Standard is not intended to function as a detailed engineering design specification for fatigue apparatus Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies ISO 2439:2008, Flexible cellular polymeric materials — Determination of hardness (indentation technique) Principle Repeated indentation of a test piece by an indentor smaller in area than the test piece, the maximum load reached during each cycle being kept within specified limits The typical loading cycle is shown in Figure A.1 Apparatus 4.1 Pounding test machine of either Type A (see 4.2) or Type B (see 4.3), having the following parts 4.1.1 Plane platen, capable of fully supporting the test piece, and suitably vented with holes approximately mm in diameter at approximately 20 mm pitch in order to allow air to escape from the test piece 4.1.2 Indentor, having an overall diameter of 250 mm ± mm with a 25 mm ± mm radius at its lower edge, provided with a device for applying a maximum force of 750 N ± 20 N during the loading cycle The indentor shall be rigidly fixed to its guide and its surface shall be smooth but not polished The machine shall be capable of oscillating either the platen (4.1.1) carrying the test piece, or the indentor towards the other in a vertical direction at a rate of (70 ± 5) strokes per minute The amplitude of the stroke shall be adjustable The indentor shall be linked to a re-settable counting device which displays the number of compression cycles performed during the test © ISO 2014 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ISO 3385:2014(E) 4.1.3 Indentor drive mechanism, capable of applying the maximum force of 750 N ± 20 N for no more than 10 % of the total duration of each cycle 4.2 Machine Type A, in its simplest form the mechanism comprises a crank drive and suspended weight The weight shall be supported throughout the loading cycle except at that part of the stroke when the mounting and platen are closest together At this point, the full force of the indentor shall be supported by the test piece; this shall not be for more than 10 % of the full machine cycle This type of device is shown schematically in Figure a) and Figure b) The moving platen (5) shall be fitted with appropriate means to locate the test piece and prevent its lateral movement during the test b) Zero load point ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - a) Full loading point Key load frame indentor mounting indentor test piece moving platen drive shaft/cam Figure — Example of an arrangement of machine Type A with manual adjustment 4.3 Machine Type B, a fully controlled device driven by electro-, pneumatic or hydraulic mechanism, equipped with load cell and means to provide the necessary indentation frequency and peak force The generic form of machine Type B is illustrated schematically in Figure Figure is an outline drawing of one of the commercially available machines, but is not meant to exclude other machines that comply with the essential requirements The apparatus shall be capable of measuring the maximum force with a precision of ±1 % Compliance with specified limits shall be provided by graphical or other visual display Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2014 – All rights reserved Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ISO 3385:2014(E) ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - Key load frame actuator (electro-mechanical, pneumatic or servo-hydraulic) indentor test piece support platen load cell Figure — Examples of diagrammatic arrangements of machine Type B with fully automatic adjustment — a) Generic design © ISO 2014 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ISO 3385:2014(E) Key beam electromechanical, pneumatic or hydraulic cylinder flow control valve load cell adapter load cell indentor test piece base plate Figure — Examples of diagrammatic arrangements of machine Type B with fully automatic adjustment — b) Example of one commercially available apparatus Type B machines shall be equipped with a force-measurement device, whereby the maximum load applied to the test piece by the indentor during every cycle shall be measured The maximum force shall be controlled within 750 N ± 20 N tolerance throughout the full duration of the pounding process The support platen (5) or base plate (8) (as appropriate) shall be fitted with appropriate means to locate the test piece and prevent its lateral movement during the test Test pieces 5.1 Shape and dimensions Test pieces shall be right parallelepipeds having sides of length 380 mm ± 20 mm and a thickness of 50 mm ± mm Tests may also be conducted on components that not comply with these dimensions subject to agreement between the interested parties Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - © ISO 2014 – All rights reserved Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ISO 3385:2014(E) 5.2 Samples showing orientation Normally, testing shall be conducted in that direction in which the finished product will be stressed under service conditions If materials show cell structure orientation, the direction in which the indentation is applied may be agreed between the interested parties 5.3 Number Three test pieces shall be tested 5.4 Conditioning 5.4.2 Prior to the test, the test pieces shall be conditioned, undistorted, for at least 16 h in one of the specified atmospheres as follows: a) 23 °C ± °C, 50 % ± % relative humidity, or b) 27 °C ± °C, 65 % ± % relative humidity This period can form the latter part of the period following manufacture Procedure 6.1 6.2 6.3 Testing shall be conducted in a climate controlled atmosphere as specified in 5.4 Perform all measurements on the same surface of the test specimen Measure the thickness, d1, and its hardness index as specified in ISO 2439:2008, Method A 6.4 Machine Type A: Place the test piece concentrically under the indentor, adjust the stroke to be equal to the thickness of the test piece with a tolerance of ±10 % and adjust the relative separation of the indentor and platen, until the specified load of 750 N ± 20 N is applied The correct loading is achieved when the indentor is just lifted in its mounting and is completely unsupported As the foam softens during pounding, it is necessary for the indentor position to be continuously adjusted during the test sequence to maintain the above test load of 750 N ± 20 N 6.5 Machine Type B: Place the test piece concentrically under the indentor and set the indentor speed to provide an indentation frequency of (70 ± 5) strokes per minute in a way that approximates to a triangular or sinusoidal travel-time sequence Apply contact between indentor and specimen and, within the first 10 preliminary loading cycles, bring peak load and dwell time under control within specified limits The maximum allowed force of 770 N shall not be exceeded at any time during the test The dwell time at peak load shall not exceed 10 % of the full period time of the indentation cycle throughout the whole test During the test, ensure that the peak load of 750 N ± 20 N is constantly within tolerance by appropriate adjustment e.g of the stroke or test speed The indentor shall be completely discharged in each loading cycle of the test © ISO 2014 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - 5.4.1 Material shall not be tested less than 72 h after manufacture, unless at either 16 h or 48 h after manufacture it can be demonstrated that the result does not differ by more than ±10 % from that obtained after 72 h Testing is permitted at either 16 h or 48 h if, at the specified time, the above criterion has been satisfied ISO 3385:2014(E) 6.6 Run the machine for 80 000 continuous load cycles and then remove the test piece from the machine and allow it to rest in an unstrained state for 10 ± 0,5 min, before performing fresh measurements on the fatigued area as described in 6.7 6.7 Re-measure the thickness d2 of the test piece as specified in ISO 2439 and then carry out the measurement of hardness index at (40 ± 1) % indentation as specified in Subclauses 7.2 and 7.3 (method A) of ISO 2439:2008, except that the (40 ± 1) % indentation level shall be calculated using the original thickness measurement d1 This requirement is illustrated schematically in Figure a) Test piece before fatigue test b) Test piece after fatigue test Key L indentation level d1 thickness of the test piece before fatigue test, expressed in millimetres d2 thickness of the test piece after fatigue test, expressed in millimetres Figure — Schematic representation of hardness re-test procedure 6.8 Repeat the whole procedure, from the measurement of the original thickness and indentation hardness, for the remaining test pieces Expression of results 7.1 Loss in thickness The percentage loss in thickness, Δd (%), is given using Formula (1): ∆d (%) = 100 × d1 − d d1 (1) where d1 is the original thickness; ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - d2 is the final thickness Express the result as the median of the values obtained for the three test pieces Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2014 – All rights reserved Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ISO 3385:2014(E) 7.2 Loss in hardness The loss in hardness, ΔH (N), is given using Formula (2): ΔH (N) = H1 – H2 (2) where H1 is the original hardness (N); H2 is the final hardness (N) Express the result as the median of the values obtained for the three test pieces 7.3 Percentage hardness loss The percentage hardness loss, ΔH (%), is given by Formula (3): ΔH (%) = 100 × (H1 – H2)/H1 where (3) H1 is the original hardness (N); H2 is the final hardness (N) Express the result as the median of the values obtained for the three test pieces Precision An ITP study was conducted in 2012 under the supervision of experts from Germany and Japan, using procedural details contained in this International Standard The results of this study are presented as Annex B Additional information from a UK study using machine Type B is contained in Annex C This study was conducted in 2008 following the requirements of ISO 3385:1989 Test report 9.1 The test report shall include the following information: a) a reference to this International Standard; c) the conditioning used; e) the predominant direction of the cellular structure, if any; b) a description of the material; d) the size and shape of the component tested, if different from the standard test piece; f) the type of machine used (Type A or B); g) the median percentage thickness loss after pounding; h) the median hardness loss after pounding; © ISO 2014 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ISO 3385:2014(E) i) the median percentage hardness loss after pounding 9.2 An example of how to express briefly the dynamic fatigue characteristics determined in accordance with this International Standard is as follows: EXAMPLE ISO 3385 median percentage thickness loss median percentage hardness loss after pounding ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2014 – All rights reserved Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ISO 3385:2014(E) Annex A (informative) Typical loading cycle Key S S1 t T T1 T2 vavg vmax a b indentor stroke indentor travel unsupported by mounting time axis time for one complete load cycle dwell time at full loading dwell time at zero load average indentor speed maximum indentor speed Indentor stroke = specimen thickness Indentor contact Figure A.1 — Graphical representation of loading cycle: manually adjusted machine ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - © ISO 2014 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ISO 3385:2014(E) Annex B (informative) Precision B.1 General An interlaboratory test program (ITP) for the precision evaluation of the pounding fatigue test machines Type A and Type B described in this International Standard for flexible cellular foam was planned and conducted in 2012 and the calculation was carried out in accordance with ISO/TR 9272 Ten different laboratories from two countries participated in Type B testing [seven laboratories used Type B b) (see Figure 3) and other three used Type B a) (see Figure 2)] in this ITP but only one laboratory used Type A machine Two samples with two different levels of hardness were prepared for this ITP as shown in Table B.1 and sent out to each laboratory which had been requested to the test as soon as the samples arrived The test was carried out in two different days at one week’s interval Each sample comprised triplicate test pieces for each day (n = 3) The precision results as determined by this ITP may not be applied to acceptance or rejection testing for any group of materials or products without documentation that the results of this precision evaluation actually apply to the products or materials tested Table B.1 — Flexible cellular foam sample Hardness level according to ISO 2439 (Average N) Sample B Low (140 N) High (300 N) Each sample was conditioned and tested according to this International Standard B.2 Precision results The precision results are summarized and given in Table B.2 This result was obtained using outlier deletion procedures as described in ISO/TR 9272, therefore the number of laboratories in Table B.2 is given after the outliers were deleted Table B.3 is for information only since only one laboratory’s data are shown Repeatability: The repeatability, r, of the test method has been established as the appropriate value tabulated in Table B.2 for each material Two single test results that differ by more than the value shall be considered suspect and suggest that some appropriate investigative action be taken Reproducibility: The reproducibility, R, of the test method has been established as the appropriate value tabulated in Table B.2 for each material Two single test results that differ by more than the value shall be considered suspect and suggest that some appropriate investigative action be taken 10 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2014 – All rights reserved Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - NOTE Sample A ISO 3385:2014(E) Table B.2 — Precision for Type B a) and Type B b) A Item Mean ∆d (%) 3,36 ∆H (N) 46,5 ∆H (N) 65,7 ∆H (%) ∆d (%) B ∆H (%) Notation used: sr r 33,3 1,55 21,9 Within laboratory Between laboratories sr r (r) sR R (R) Number of laboratories 0,15 0,43 13 0,51 1,43 43 21 0,21 4,65 13,2 28 2,36 6,70 10 0,87 2,45 0,12 0,33 0,86 2,44 is the repeatability standard deviation; 7,14 44 10 32,3 49 2,91 8,25 3,30 9,30 0,59 11,4 11 20,2 25 38 43 ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - Sample is the repeatability, in measurement units; (r) is the repeatability, in percent (relative); sR R is the reproducibility standard deviation; is the reproducibility, in measurement units; (R) is the reproducibility, in percent (relative) Table B.3 — Precision for Type A Sample A B Notation used: sr r Item Mean ∆d (%) 3,6 ∆H (N) ∆H (%) ∆d (%) ∆H (N) ∆H (%) is the repeatability standard deviation; 54,1 Within laboratory sr r (r) Number of laboratories 0,6 1,6 44,0 17,2 7,4 20,8 38,5 5,6 15,6 18,4 38,4 2,8 30,2 2,0 1,2 85,2 0,1 7,9 0,2 5,5 20,6 18,4 1 1 is the repeatability, in measurement units; (r) is the repeatability, in percent (relative) © ISO 2014 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS 11 Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ISO 3385:2014(E) Annex C (informative) Precision study — Machine Type B C.1 General A precision study was commissioned by the UK during 2008 A total of 18 different grades of flexible polyurethane foam with widely divergent physical properties and chemistry were tested to ISO 3385:1989 using a Type B machine at a nationally accredited independent test laboratory Hardness loss and height loss were measured in triplicate for each of the 18 materials Results are shown in Table C.1 Table C.1 — Precision results Foam i ii 7,7 6,5 5,4 2,4 2,5 2,1 1,0 % iii median 6,4 6,5 6,4 2,4 2,3 3,4 3,6 2,8 0,5 3,0 1,2 2,4 2,8 15,0 10 3,8 3,5 3,2 3,5 11 12 13 2,8 4,9 3,6 4,4 18 4,4 5,1 4,1 17 4,7 3,1 2,8 4,6 4,4 2,0 3,3 2,8 3,5 16 3,9 3,8 14 15 2,5 4,3 4,6 3,8 2,5 7,1 ii iii median 57 57 53 57 36 35 36 72 72 25 25 31 29 22 23 30 5,7 38 36,0 81 5,9 20,0 5,3 25 33 20 72 32 35 22 25 37 34 40 31 29 27 3,2 22 4,5 33 25 34 4,4 15,9 44 46 41 44 23,7 54 51 49 51 3,8 4,4 3,8 35,7 7,9 13,2 7,3 4,5 2,4 21,1 9,5 36 39 62 50 32 35 58 50 38 37 69 55 20 8,1 6,9 8,8 6,8 4,5 11,1 62 6,5 50 5,6 12,7 36 37 6,1 6,9 34 7,1 20 29 34 24 2,8 8,1 37 20,5 27 9,1 37 9,1 25,6 8,6 20 6,5 15,2 8,6 19 7,0 % 31 3,3 3,9 4,2 C.2 Precision results i 20 4,2 3,0 6,0 18,5 N 12,0 2,8 4,1 50,0 % Deviation from median 20,0 2,6 3,8 10,0 2,6 15,0 3,7 25,0 3,8 1,0 14,1 3,8 4,2 26,5 20,4 4,0 1,5 3,4 Hardness loss Deviation from median 5,4 3,9 5,6 5,4 11,3 10,0 5,9 As required by ISO 3385:1989, the median height loss and median hardness loss were identified This was done for each of triplicate data sets representing the 18 different foam grades Individual height loss measurements (in millimetres, mm) deviated from the median value by, on average, 13,7 % Individual hardness loss measurements (in newtons, N) deviated from the median value by, on average, 5,8 % 12 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2014 – All rights reserved Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - Hardness loss ISO 3385:2014(E) Bibliography ISO/TR 9272, Rubber and rubber products — Determination of precision for test method standards ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - [1] © ISO 2014 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS 13 Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST ```,`,`,,``,,````,,,,,``,`,,-`-`,,`,,`,`,,` - ISO 3385:2014(E) ICS 83.100 Price based on 13 pages © ISO 2014 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Licensee=University of Alberta/5966844001, User=ahmadi, rozita Not for Resale, 01/26/2015 09:44:10 MST